Conventionally, a stator of a rotating electric machine includes a cylindrical stator core and stator coils. The stator core includes a plurality of teeth (magnetic poles) radially arranged and projecting radially inwardly and a plurality of slots open between the teeth. The stator coils are mounted on the stator core by housing a coil side portion into each slot.
A so-called inserter method (see, for example, JP2001-513320A) is known concerning this mounting of stator coils. In the inserter method, stator coils are fabricated in advance separately from a stator core and these stator coils are mounted into each slot of the stator core using an inserter device.
In this inserter method, the stator coils are mounted by pulling up the stator coils by a push-up shaft of the inserter device and moving these stator coils upwardly while pushing the stator coils into the slots of the stator core. After the mounting of the stator coils, the stator coils are wound around separate slots parallel to an axial direction of the stator core.
Parts of the stator coils housed in the slots between the teeth constitutes stator coil side portions and the remaining parts not inserted into the slots of the stator coil constitute coil end portions projecting from an end surface of the stator core.
Here, the coil end portions need to be located on the upper surface of the push-up shaft of the unillustrated inserter device when the mounting of the stator coils is completed. Thus, in this inserter method, the size of the stator coils is set such that the coil end portions are located on the upper surface of the unillustrated push-up shaft when the mounting of the coils is completed.
On the other hand, since a rotor is inserted into this stator, it is necessary to prevent the coil end portions projecting from the axial end surface of the stator core without being housed in the slots from protruding more inwardly than the inner peripheral surface of the stator core.
Further, if the rotating electric machine is of a three-phase type, stator coils of three phases are mounted on a single stator core. Thus, in the rotating electric machine of the three-phase type, coil end portions of three phases projecting from the slots for each phase coil overlap each other.
In consideration of this, in a conventional manufacturing method, molding is performed to allow coil end portions of stator coils mounted first and projecting from slots to escape to a radially outer side of the stator core and, thereafter, other stator coils are inserted into slots. After the stator coils of three phases are mounted on the single stator core, molding is performed to let all the coil end portions of the phase stator coils to escape to the radially outer side again, thereby preventing the coil end portions of the stator coils of all the three phases from entering more inwardly than the inner peripheral surface of the stator core.